Infectious diseases of a domestic animal cause a weight decrease of the domestic animal and induce various pathologies, and hence remarkably lower the commercial value of the domestic animal. For example, Staphylococcus aureus is a bacterium causing mastitis, subcutaneous tumor, and pyemia of bovines, sheep, and goats, anthema of horses, and arthritis, dermatitis, and ichorrhemia of pigs and chickens. Further, Streptococcus suis is a bacterium causing meningitis, ichorrhemia, endocarditis, and arthritis of pigs, and Streptococcus bovis is a bacterium causing a bloat of bovines.
The bloat refers to the following state: rumen juice is formed into a foamed state so that gas is not separated from liquid, and the accumulated gas cannot be expelled by eructation. The gas compresses the heart and the lungs, and the animal dies when they are left as it is. When the animal is fed with a feed containing a small amount of coarse feed and a large amount of starch such as corn, Streptococcus bovis increases in the rumen, and the rumen juice is formed into a foamed state due to the generated viscous substance.
It is known that cashew nut shell liquid has an antibacterial action (Non-patent Document 1) and a coccidiosis-relieving action (Patent Document 1).
Further, it is reported that the cashew nut shell liquid has antibacterial action against Gram-positive bacteria such as Staphylococcus aureus, Streptococcus mutans, Bacillus subtilis, and Bacillus ammoniagenes, and does not have antimicrobial action against Gram-negative bacteria such as Escherichia coli, Enterobacter aerogenes, and Pseudomonas aeruginosa, and against fungi such as Saccharomyces cerevisiae, Candida Utilis, and Penichillium chrysogenum (Non-patent Document 2). However, the antibacterial action of the cashew nut shell liquid against S. bovis is not known, and there is no report at all on the preventive effect against a bloat.
Patent Document 1: JP 08-231410 A
Non-patent Document 1: Muroi, H. et al., Bioorganic & Medicinal Chemistry 12, 583-587 (2004)
Non-patent Document 2: Himejima M. and Kubo I., J. Agric. Food Chem., 39, 418-421 (1991)